Issue No. 05 - May (2008 vol. 19)
In this paper, we investigate the theoretical aspects of the nonuniform node distribution strategy used to mitigate the energy hole problem in wireless sensor networks (WSNs). We conclude that in a circular multihop sensor network (modeled as concentric coronas) with nonuniform node distribution and constant data reporting, the unbalanced energy depletion among all the nodes in the network is unavoidable. Even if the nodes in the inner coronas of the network have used up their energy simultaneously, the ones in the outmost corona may still have unused energy. This is due to the intrinsic many-to-one data traffic pattern of WSNs. Nevertheless, near balanced energy depletion in the network is possible only if the number of nodes increases in geometric progression from the outer coronas to the inner ones except the outmost one. Based on the analysis, we propose a novel nonuniform node distribution strategy to achieve the near balanced energy depletion in the network. We regulate the number of nodes in each corona and derive the ratio between the node densities in the adjacent (i+1)-th and i-th coronas by the strategy. Finally, we propose q-Switch Routing, a distributed shortest path routing algorithm tailored for the proposed nonuniform node distribution strategy. Extensive simulations have been performed to validate the analysis.
Sensor networks, Wireless communication
X. Wu, S. K. Das and G. Chen, "Avoiding Energy Holes in Wireless Sensor Networks with Nonuniform Node Distribution," in IEEE Transactions on Parallel & Distributed Systems, vol. 19, no. , pp. 710-720, 2007.